Jackie Ballard is a survivor. In 2002, when her appointment as director-general of the RSPCA was announced, a storm broke over her head. She was publicly lambasted by RSPCA members, four trustees resigned in protest and her political background and character was subjected to a media assault. The headlines focused on her political background, gender and management inexperience, all of which her detractors claimed rendered her incapable of leading the RSPCA out of financial crisis. The Daily Mail branded her "a feminist and failed MP who hates hunting and can't even read a balance sheet".

Five years on, Ballard's critics have been silenced. She has emerged as one of the voluntary sector's leading modernisers, turning around a nationally cherished institution, and is now completing her first month in her new role as chief executive of the RNID for deaf and hard of hearing people, one of UK's largest service delivery charities, respected for its innovative approach to care services and accountability initiatives.

"Of course I feel vindicated," says Ballard. "It was a truly awful start [at the RSPCA], but the only way you can really confront your critics is by proving them wrong, and in the end my actions spoke louder than their words. I left the RSPCA a 10-times healthier charity than when I joined, which is vindication enough," she says.

She believes that a lot of the flak she faced over her RSPCA appointment was linked to the "fierce loyalty" that the charity inspires among its more traditional members. "There was a sense of how things were done there," she says. "I think they were expecting another major-general type and instead they got me." Ballard caused a stir on her first day by asking staff to address her as Jackie rather than director-general or DG, as had been done before.

"Things have changed now, but even five years ago there was perhaps a sense that a woman wasn't the right choice for what was essentially a quasi-military institution, let alone a [former] liberal MP who had just come back from Iran. But I put my head down and concentrated on the job in hand."

Archaic operations

That meant digging the charity out of a deep financial hole of its own making. Against stiff resistance from her trustee board, Ballard pushed through a tough reform of the charity's archaic operations and in doing so pulled the RSPCA back from the brink, wiped out its £7m deficit and raised income from £80m in 2002 to £111m in 2006. She oversaw the implementation of a new Animal Welfare Act and a £6.5m programme of animal centre refurbishments.

Then, just as things were running smoothly, she was off to the RNID. Didn't she feel she deserved a bit of time to rest on her laurels? "I sometimes ask myself the same question," she says, laughing. "But I've always operated my life by disrupting it. I get bored quite easily and when I know how to do something I start to think that I'm of less value, that I'm not going to be as sharp as I could be."

Ballard believes that the RNID position provides her with an opportunity to return to a path of helping improve people's lives which she started in her first job as a social worker, and gives her a chance to fight discrimination around the "hidden disability" of deafness. "The RNID is a much more streamlined and efficient charity, and thank God it isn't facing a financial crisis, but there is everything to play for in this field," she says.

"There's a really big job to be done, whether it's fighting for better legislation or employment practice, helping improve the everyday quality of life for deaf and hard of hearing people or ensuring that we keep improving public service delivery in this area. In many ways, attitudes to hearing disability are worse than a lot of other disabilities so this presents a tremendous challenge, and one I feel I'm equipped to handle."

Throughout her career, Ballard has always come out fighting for the causes she believes in. It was her voracious campaigning for animal rights while a Liberal Democrat MP for Taunton in the late 1990s that led her to the RSPCA after her vocal anti-hunting stance proved unpopular with voters in Somerset and ended her career as a politician in 2001.

She says her experience at the RSPCA has taught her valuable lessons about leadership and acknowledges that the maelstrom she faced was partly of her own making; she cringes at her "unbelievable naivety" in giving candid personal interviews before she had spent one working day in post.

One profile, printed in the Telegraph, had Ballard expounding her "radical" personal views on everything from fishing to shooting to wearing fur, which forced her staff into the unfortunate position of having to launch a defence of a new chief executive they had not even met.

"I have learned the hard way that the difference between this life and my political life is that as a politician when I spoke I generally felt it was me I was representing, whereas when you're chief exec of a large national charity you've got to remember you're representing the organisation first and foremost."

She pauses: "The real truth is that when I was a politician I learned to be sceptical about journalists, especially when it feels cosy and as though you're having a nice chat over a cup of coffee. But in the year I had out studying in Iran before joining the RSPCA, I forgot all this. And my real mistake was that I forgot that journalists are only ever looking for a meaty story. I let my guard down. I gave it to them on a plate really."

It is not an experience Ballard is prepared to repeat. Her intention at the RNID is to keep the charity in the spotlight as much as possible and herself out of it.

She acknowledges that her RNID appointment has caused a certain amount of consternation among some ranks of the charity's membership indignant about another "hearie" being chosen to lead the charity. "Of course I expected those opinions to be expressed one way or another," says Ballard. "And, of course, if there was an equally capable candidate who was deaf, the job should have gone to them. But the trustees have a responsibility to appoint the person they think best suits the role, and they thought that was me.

"I might have a background in campaigning but that's not why I'm here. I'm here because of my knowledge of the voluntary sector, my understanding of the lobbying process and my track record in running a large complicated organisation, and running it well."

There are signs Ballard's leadership will ring some changes. Although the RNID derives 70% of its £50m annual income from statutory public service contracts, she strikes a more sceptical note than her predecessor, John Low, about the relationship between government and the voluntary sector: "Having been one, I'm more cynical about politicians and the government's position on the transferral of public services to the voluntary sector."

"I think that the wholesale transfer of services is attractive to politicians for many reasons, including because they think it's a cheaper or more popular alternative to the private sector but also because it's arm's length accountability."

Proceed with caution

And she has concerns about that: "The government and its ministers have to be held accountable for essential services, and I think the voluntary sector would have to change fundamentally to be able to say it's accountable to the public. We have to proceed cautiously."

When asked whether she would consider moving back to politics, Ballard is aghast. "Absolutely not. I've changed immeasurably since my days as a politician and I would never want to go back," she says. "One of my hangovers from being a politician was often that I lacked humility. Since I stopped being one, I've learned humility, the ability to listen more. Under my leadership, I want a higher profile for the RNID and a higher profile for the cause, but I'm certainly not after a high profile for Jackie Ballard. Quite the opposite."

Curriculum Vitae

Age 54.

Status Single, one daughter.

Lives London.

Education Monmouth school for girls, Abergavenny; London School of Economics, social psychology (BSc).